A087681 Numbers n such that n + 6 and n - 6 are both prime.

11, 13, 17, 23, 25, 35, 37, 47, 53, 65, 67, 73, 77, 95, 103, 107, 133, 143, 145, 157, 173, 185, 187, 205, 217, 233, 235, 245, 257, 263, 275, 277, 287, 343, 353, 373, 395, 403, 415, 425, 427, 437, 455, 473, 485, 493, 497, 515, 563, 593, 607, 613, 625, 637, 647

Offset

1,1

Comments

Many terms are of the form 5 + n + n^2 or 5 + 2*n^2: A054794.

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Mathematica

f[n_]:=PrimeQ[n-6]&&PrimeQ[n+6]; lst={}; Do[If[f[n], AppendTo[lst, n]], {n, 2, 7!, 1}]; lst (* Vladimir Joseph Stephan Orlovsky, Aug 12 2009 *)
Select[Range[2, 700], AllTrue[#+{6, -6}, PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Jan 26 2019 *)

Crossrefs

Cf. A054794.

Cf. A014574, A087678-A087683, A087695-A087697, A088766.

Sequence in context: A036977 A120168 A260715 * A137669 A360979 A152470

Adjacent sequences: A087678 A087679 A087680 * A087682 A087683 A087684

Keyword

easy,nonn

Author

Zak Seidov, Sep 27 2003

Status

approved